Abstract
Previous studies indicated that heavy mineralogy (specific gravity (SG) = 2.8-3.2 and >3.2) of the medium-sand fraction (0.25-0.50 mm) of till contains porphyry copper indicator minerals (PCIM) derived from mineralization or alteration zones. To improve the PCIM method for mineral exploration, we analyzed the heavy mineralogy (>3.2 SG) of the fine-sand fraction (0.125-0.180 mm) of till using an automated method that combines scanning electron microscopy (SEM) and mineral-liberation analysis (MLA). The MLA-SEM method identifies mineralogy based on grain composition determined by SEM-energy dispersive spectroscopy. The distributions of epidote and chalcopyrite in till at four porphyry copper deposits in British Columbia show similarities between the fine-sand fraction analyzed by MLA-SEM and the medium-sand fraction analyzed by optical mineralogy: both show dispersal parallel to ice-flow movements. Analyzing the fine-sand, heavy-mineral concentrate (HMC) fraction of till by MLA-SEM can be used in exploration for porphyry copper mineralization. We estimate 5 to 8 kg of bulk till is sufficient to prepare 0.3 g aliquots of fine-sand HMC for MLA-SEM; this is smaller than the 9 to 15 kg required for optical mineral analysis of the medium-sand HMC fraction. Smaller field samples can lower costs for reconnaissance mineral exploration.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
